Transitional cell carcinoma involving the ductus deferens in a dog.

CASE DESCRIPTION: A 12-year-old neutered male Springer Spaniel was referred with a 1-year history of recurring urinary tract infections. Repeated treatment with appropriate antimicrobials selected on the basis of bacterial culture and antimicrobial susceptibility results would result in clinical improvement, but recurrence of clinical signs was observed within days after discontinuation of treatment. CLINICAL FINDINGS: Ultrasound examination revealed a tubular, fluid-filled structure dorsal to the bladder that extended from the midlevel of the bladder to the cranial pole of the prostate. Mineralized foci within a heterogeneous prostatic parenchyma were also noted. Dilation of the right ductus deferens (DD) was observed during exploratory laparotomy. TREATMENT AND OUTCOME: Both DD were surgically removed, and the prostate was biopsied. The histopathological diagnosis was transitional cell carcinoma involving the right DD and the prostate. The dog was treated with meloxicam (0.1 mg/kg [0.05 mg/lb], p.o., q 24 h) for 9 months after diagnosis before being euthanized. CLINICAL RELEVANCE: Because the normal DD is rarely visualized during abdominal ultrasonography in dogs, identification of a tubular, fluid-filled structure dorsal to the bladder may indicate an abnormal DD. Transitional cell carcinoma of the DD should be included in the differential diagnoses of affected patients examined for clinical signs involving the urinary tract.

Zygomatic salivary mucocoele as a postoperative complication following caudal hemimaxillectomy in a dog.

Zygomatic mucocoele is reported as a postoperative complication occurring secondary to a caudal hemimaxillectomy in a two-year-old Labrador retriever. The dog was presented with a history of a rapidly growing oral mass, identified as a soft tissue sarcoma. A caudal hemimaxillectomy via an intraoral approach was performed as treatment for local control of the oral mass. Fifteen days postoperatively, periorbital swelling and exophthalmos developed on the ipsilateral side. The degree of swelling progressed and was identified by computed tomography, ultrasound and cytology as a salivary mucocoele. Zygomatic sialoadenectomy was performed via a modified lateral approach with zygomatic osteotomy. A small amount of discharge persisted from the surgical site but gradually resolved. Recurrence of the periorbital swelling and exophthalmos was noted 25 days later and further surgery was performed to excise residual salivary tissue. Adjuvant radiotherapy was performed, however local recurrence of the oral mass was identified 5 months postoperatively and the patient subsequently euthanased. Salivary mucocoele has been cited as a possible postoperative complication following maxillectomy and mandibulectomy procedures; however to the authors' knowledge, only one previous case report exists in the literature. The current case documents a zygomatic salivary mucocoele occurring subsequent to caudal hemimaxillectomy.

Regulation of COX-2 expression in canine prostate carcinoma: increased COX-2 expression is not related to inflammation.

BACKGROUND: Cyclooxygenase-2 (COX-2) expression has been documented in human and canine prostate carcinoma (PCA). Canine PCA is a histologically heterogeneous tumor, sometimes including inflammatory infiltrates. However, it is unknown whether COX-2 expression in canine PCA is related to the histologic type of tumor, to the presence of inflammation, or to both. Moreover, little is known about the mechanisms regulating COX-2 expression in neoplastic tissue. HYPOTHESIS: COX-2 expression is related to the presence of inflammation in canine PCA and correlates with the degree of tumor differentiation. METHODS: The expression of COX-2 was examined in 28 cases of canine PCA by immunohistochemistry. In addition, a neoplastic and a nonneoplastic canine prostatic cell line were used to investigate the effects of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), phorbol 12-myristate 13-acetate (PMA), epithelial growth factor (EGF), and specific signal transduction pathway inhibitors on COX-2 expression. RESULTS: Twenty-four of the 28 prostate tumors showed COX-2 expression. The presence of inflammatory infiltrates in tumor tissue was associated with lower COX-2 expression scores. In vitro, TNF-alpha, IL-6, and EGF increased COX-2 expression in nonneoplastic cells but not in PCA cells, where baseline expression was high. COX-2 expression in PCA cells could be suppressed by means of specific phosphatidyl inositol-3 kinase (PI3K), protein kinase C (PKC), or inhibitor of extracellular signal-related kinase (ERK/MAPK) inhibitors. CONCLUSIONS AND CLINICAL IMPORTANCE: COX-2 is expressed in canine PCA; however, expression is not related to the presence of inflammatory infiltrates. This conclusion is further supported by the finding that the cytokines TNF-alpha and IL-6 and their involved signaling pathways do not stimulate COX-2 expression in malignant canine prostate cells.

Partial prostatectomy using Nd:YAG laser for management of canine prostate carcinoma.

OBJECTIVE: To report a technique for partial prostatectomy by laser dissection and to evaluate outcome and complications in dogs with prostate carcinoma (PCA). STUDY DESIGN: Experimental and clinical case series. ANIMALS: Four normal dogs and 8 dogs with PCA. METHODS: Subcapsular partial prostatectomy, sparing the urethra and the dorsal aspect of the prostatic capsule, using Nd:YAG laser dissection to remove the prostatic parenchyma and control hemorrhage was performed in 4 normal dogs and subsequently in 8 dogs with histologically confirmed PCA. Additional treatment of PCA dogs included local application of interleukin-2 and systemic administration of meloxicam. Prostate size, complications, and survival time were recorded. Laser-associated thermal damage to surrounding tissue was evaluated by histology. RESULTS: In normal dogs, no damage to the dorsal prostatic capsule or urethra was detected. In PCA dogs, median survival was 103 days (range, 5-239 days). Three dogs died from complications within 16 days, whereas 5 (median survival, 183 days; range, 91-239 days) had improvement or resolution of clinical signs. Urinary incontinence did not occur. CONCLUSION: Laser assisted subcapsular partial prostatectomy can be performed in dogs with PCA without development of postoperative incontinence. CLINICAL RELEVANCE: Subcapsular partial prostatectomy is a potential palliative treatment for PCA in dogs and may lead to the resolution of clinical signs for several months.